package com.google.gwt.sample.stockwatcher.client;

import java.util.ArrayList;
import java.util.Date;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.core.client.GWT;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyPressEvent;
import com.google.gwt.event.dom.client.KeyPressHandler;
import com.google.gwt.i18n.client.DateTimeFormat;
import com.google.gwt.i18n.client.NumberFormat;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.FlexTable;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.TextBox;
import com.google.gwt.user.client.ui.VerticalPanel;
import com.google.gwt.user.client.rpc.AsyncCallback;

public class StockWatcher implements EntryPoint {

	private static final int REFRESH_INTERVAL = 5000; // ms
	private VerticalPanel mainPanel = new VerticalPanel();
	private FlexTable stocksFlexTable = new FlexTable();
	private HorizontalPanel addPanel = new HorizontalPanel();
	private TextBox newSymbolTextBox = new TextBox();
	private Button addStockButton = new Button("Add");
	private Label lastUpdatedLabel = new Label();
	private ArrayList<String> stocks = new ArrayList<String>();
	private StockPriceServiceAsync stockPriceSvc = GWT.create(StockPriceService.class);
	private Label errorMsgLabel = new Label();

  /**
   * Entry point method.
   */
  public void onModuleLoad() {

	  // Create table for stock data.
	  stocksFlexTable.setText(0, 0, "Symbol");
	  stocksFlexTable.setText(0, 1, "Price");
	  stocksFlexTable.setText(0, 2, "Change");
	  stocksFlexTable.setText(0, 3, "Remove");
	  
	  // Add styles to elements in the stock list table.
	  stocksFlexTable.setCellPadding(6);
	  stocksFlexTable.getRowFormatter().addStyleName(0, "watchListHeader");
	  stocksFlexTable.addStyleName("watchList");
	  stocksFlexTable.getCellFormatter().addStyleName(0, 1, "watchListNumericColumn");
	  stocksFlexTable.getCellFormatter().addStyleName(0, 2, "watchListNumericColumn");
	  stocksFlexTable.getCellFormatter().addStyleName(0, 3, "watchListRemoveColumn");
	  // Assemble Add Stock panel.
	  addPanel.add(newSymbolTextBox);
	  addPanel.add(addStockButton);
	  addPanel.addStyleName("addPanel");

	    // Assemble Main panel.
	  errorMsgLabel.setStyleName("errorMessage");
	  errorMsgLabel.setVisible(false);
	  
	  mainPanel.add(errorMsgLabel);
	  mainPanel.add(stocksFlexTable);
	  mainPanel.add(addPanel);
	  mainPanel.add(lastUpdatedLabel);
	  

	  // Associate the Main panel with the HTML host page.
	  RootPanel.get("stockList").add(mainPanel);

	  // Move cursor focus to the input box.
	  newSymbolTextBox.setFocus(true);
	  
	  // Setup timer to refresh list automatically.
	  Timer refreshTimer = new Timer() {
		  @Override
	      public void run() {
			  refreshWatchList();
	      }
	    };
	    refreshTimer.scheduleRepeating(REFRESH_INTERVAL);

	  // Listen for mouse events on the Add button.
	  addStockButton.addClickHandler(new ClickHandler() {
		  public void onClick(ClickEvent event) {
			  addStock();
	      }
	    });
	  
		// Listen for keyboard events in the input box.
		newSymbolTextBox.addKeyPressHandler(new KeyPressHandler() {
		  public void onKeyPress(KeyPressEvent event) {
		    if (event.getCharCode() == KeyCodes.KEY_ENTER) {
		      addStock();
		    }
		  }
		});


	  }

	  /**
	   * Add stock to FlexTable. Executed when the user clicks the addStockButton or
	   * presses enter in the newSymbolTextBox.
	   */
	  private void addStock() {
		    final String symbol = newSymbolTextBox.getText().toUpperCase().trim();
		    newSymbolTextBox.setFocus(true);

		    // Stock code must be between 1 and 10 chars that are numbers, letters, or dots.
		    if (!symbol.matches("^[0-9A-Z\\.]{1,10}$")) {
		      Window.alert("'" + symbol + "' is not a valid symbol.");
		      newSymbolTextBox.selectAll();
		      return;
		    }

		    newSymbolTextBox.setText("");
		    // Don't add the stock if it's already in the table.
		    if (stocks.contains(symbol))
		        return;
		    
		    // Add the stock to the table.
		    int row = stocksFlexTable.getRowCount();
		    stocks.add(symbol);
		    stocksFlexTable.setText(row, 0, symbol);
		    stocksFlexTable.setWidget(row, 2, new Label());
		    stocksFlexTable.getCellFormatter().addStyleName(row, 1, "watchListNumericColumn");
		    stocksFlexTable.getCellFormatter().addStyleName(row, 2, "watchListNumericColumn");
		    stocksFlexTable.getCellFormatter().addStyleName(row, 3, "watchListRemoveColumn");

		    // Add a button to remove this stock from the table.
		    Button removeStockButton = new Button("x");
		    removeStockButton.addStyleDependentName("remove");
		    removeStockButton.addClickHandler(new ClickHandler() {
		      public void onClick(ClickEvent event) {
		        int removedIndex = stocks.indexOf(symbol);
		        stocks.remove(removedIndex);
		        stocksFlexTable.removeRow(removedIndex + 1);
		      }
		    });
		    stocksFlexTable.setWidget(row, 3, removeStockButton);

		    // Get the stock price.
		    refreshWatchList();
	  }
	  /**
	   * Generate random stock prices.
	   */
	  private void refreshWatchList() {
		    // Initialize the service proxy.
		    if (stockPriceSvc == null) {
		      stockPriceSvc = GWT.create(StockPriceService.class);
		    }

		    // Set up the callback object.
		    AsyncCallback<StockPrice[]> callback = new AsyncCallback<StockPrice[]>() {
		      public void onFailure(Throwable caught) {
		          // If the stock code is in the list of delisted codes, display an error message.
		          String details = caught.getMessage();
		          if (caught instanceof DelistedException) {
		            details = "Company '" + ((DelistedException)caught).getSymbol() + "' was delisted";
		          }

		          errorMsgLabel.setText("Error: " + details);
		          errorMsgLabel.setVisible(true);
		      }

		      public void onSuccess(StockPrice[] result) {
		        updateTable(result);
		      }
		    };

		    // Make the call to the stock price service.
		    stockPriceSvc.getPrices(stocks.toArray(new String[0]), callback);
	  }
	  
	  /**
	   * Update the Price and Change fields all the rows in the stock table.
	   *
	   * @param prices Stock data for all rows.
	   */
	  @SuppressWarnings("deprecation")
	private void updateTable(StockPrice[] prices) {
	    for (int i = 0; i < prices.length; i++) {
	      updateTable(prices[i]);
	    }
	    // Display timestamp showing last refresh.
	    lastUpdatedLabel.setText("Last update : "
	        + DateTimeFormat.getMediumDateTimeFormat().format(new Date()));
	    // Clear any errors.
	    errorMsgLabel.setVisible(false);
	  }
	    /**
	     * Update a single row in the stock table.
	     *
	     * @param price Stock data for a single row.
	     */
	    private void updateTable(StockPrice price) {
	      // Make sure the stock is still in the stock table.
	      if (!stocks.contains(price.getSymbol())) {
	        return;
	      }

	      int row = stocks.indexOf(price.getSymbol()) + 1;

	      // Format the data in the Price and Change fields.
	      String priceText = NumberFormat.getFormat("#,##0.00").format(price.getPrice());
	      NumberFormat changeFormat = NumberFormat.getFormat("+#,##0.00;-#,##0.00");
	      String changeText = changeFormat.format(price.getChange());
	      String changePercentText = changeFormat.format(price.getChangePercent());

	      // Populate the Price and Change fields with new data.
	      stocksFlexTable.setText(row, 1, priceText);
	      Label changeWidget = (Label)stocksFlexTable.getWidget(row, 2);
	      changeWidget.setText(changeText + " (" + changePercentText + "%)");
	      
	      // Change the color of text in the Change field based on its value.
	      String changeStyleName = "noChange";
	      if (price.getChangePercent() < -0.1f) {
	        changeStyleName = "negativeChange";
	      }
	      else if (price.getChangePercent() > 0.1f) {
	        changeStyleName = "positiveChange";
	      }

	      changeWidget.setStyleName(changeStyleName);
	    }	    
}